OS X playback aspect/zoom starts out wrong

Description

For many months, 16:9 content has appeared as a 4:3 rectangle in a 16:9 window, probably due to changes in video embedding (or other videooutput base stuff). Cycling through the zoom modes eventually fixes it. Cycling aspect ratios fixes it faster.
Very old versions (e.g. d9c4bd18fa0, c12e7d79c May/June? 2011) don't have the fault. Slightly less old (2f3acf1184 from July 31, 2011) seem to. I'm still trying to narrow down the change.

Oldest firstNewest firstThreaded

Show commentsShow property changes

Change History (2)

OK, c79525800 causes the fault. It is a reversion of 7f371230e0, which closed #9891. That ticket mentions Live TV only, and I have only tested with DVB recording playback, so maybe I will also have to test TV also :-(
There were also a few other tickets, like #9847, #9879, #9992, #10210, #10224. Too many for me to easily narrow down specific code changes. Looks like I will also have to spend many days Linux compiling and testing. 2x :-(